Just from first glance, there's a large problem with timesheet.htm, namely in that document.timeform is incorrect syntax. IE is not very forgiving, whereas other browsers are more forgiving and probably can make sense of what you're trying to do.
// change document.timeform to either:
var myForm = document.forms OR document.forms['timeform'];
// to get an element from this form:
myForm.elements[j]; // for your for loop
Also, you have your event handler stored as var e (slightly unusual naming convention) but if this is going to be a reasonably large project, normally you'd also use a target handler. I'm not sure if you have one elsewhere in your code but not in the snippet.
The sudoku solver snippet that you provided seems correct and since there's over 400 lines of JS for it, if there's something wrong, could you narrow down the block of code? I'm guessing you're just showing it for inspiration, however, a word of caution is prototype with DOM can be a bit of a headache. IE will likely extend this to a full-blown migraine (newer versions of IE might not) but you're going to have to do a lot of debugging and testing if you want to pull off that sudoku solver or something similar using prototype.